There are various types of sofas available in the markets. Most of these sofas are designed to have framework made of rigid or hard materials and are therefore bulky and heavy. Each such sofa with rigid framework occupies a fixed space and can not be easily moved due to its volume and weight. For these reasons, sofas are generally limited to indoor use. However, people pay more and more attention to their outdoor activities at leisure time and would prefer to have a comfortable sofa which has simple structure and light weight and can be conveniently transported for use indoors and/or outdoors. It is therefore tried by the inventor to develop an inflatable sofa which is simple and light and can be quickly inflated for use or deflated for convenient transporting or storage without occupying too much space.